20 Cents - Elizabeth II 4th Portrait - 1966 Decimal Pattern

Australia's decimal currency launched on 14 February 1966, but the original 20-cent dies were cut years before that date as part of an extended preparation process. The Royal Australian Mint issued this 2009 restrike using those earlier portrait dies — the fourth Machin-style effigy — to document the design sequence that preceded circulation coinage, making it a retrospective piece rather than anything that ever passed through commerce.

The 1966 pattern series was revisited partly to address collector demand for a coherent documentary set of pre-decimal and early decimal design progressions.